Behaviour of Streptococcus lactis in heat treated (80 ºC for 30 min) or sterilized cow's and ewe's milk
Generation times and acid production after 6 and 24 h by 20 strains of Streptococcus lactis of dairy origin were determined in heat treated (80 C for 30 min) and sterilized cow's and ewe's milk. Ewe's milk enhanced growth of the streptococci, with significantly (P &A;0.001) shorter generation times and higher acid production after 6 h incubation than cow's milk, probably due to its higher vitamin content. The stronger buffer capacity of ewe's milk allowed a higher (P &A;0.001) acid production after 24 h than cow's milk. A stimulatory effect of sterilization on generation time and acid production after 24 h was observed in cow's milk. However, the heat treated ewe's milk was shown to be a better substrate than sterilized ewe's milk for Str. lactis. We thank C. Garc ía-Aser and M. A. Rodríguez-Marín for N determinations and C. Burbano for Ca and Mg analysis. © 1983, Proprietors of Journal of Dairy Research. All rights reserved.
| Main Authors: | , , |
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| Format: | journal article biblioteca |
| Language: | eng |
| Published: |
1983
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| Online Access: | http://hdl.handle.net/20.500.12792/5857 |
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